1. Field of the Invention
The present invention relates generally to high performance ammunition and more particularly, to a cartridge case with the capability of splitting during firing to make the case easy to extract or eject in a push-through system. Such a cartridge case is especially useful and advantageous in telescoped ammunition systems.
2. Prior Art
Ammunition systems which employ push-through techniques to dispose of a spent cartridge case after a round has been fired, must overcome the inherent problems of case expansion or obturation due to the extreme gas pressures produced during firing. Such case expansion can permanently deform a cartridge case due to residual hoop strain in the cartridge case wall until it becomes jammed in the gun chamber and disables the gun until the cartridge case can be forcefully removed, usually only with great difficulty.
Any solution to this problem must still seal the cartridge case prior to firing and preferably during the initial stages of ignition to permit sufficient increase in gas pressures to propel the projectile with desired acceleration, muzzle velocity and other ballistic parameters. Furthermore, the cartridge cast must provide load support for the ammunition round during transport and handling and it must protect the solid propellant material within the cartridge case to guard against propellant fracture or the entry of moisture or other contaminants which might otherwise detrimentally affect ballistic performance of the round.
One prior art attempt at solving this problem has been the rolled cartridge case wherein the cartridge case wall comprises numerous overlapping layers of a thin walled rolled structure. Unfortunately, such a structure creates end-seal retention problems that would otherwise complicate the case configuration. Furthermore, the rolled case configuration does not solve the premature gas leakage or load support problems previously mentioned. Furthermore, a rolled configuration can present other difficulties associated with a discontinuity along the interior of the cartridge case wall.
There is therefore a long-felt need for an improved cartridge case which overcomes the aforementioned difficulties and this need has not been satisfied by the prior art.